> hello to all -
> i recently traded for an a-110 vco (thanks, david, great trade !)
> to add to
> my system with the specific intention of adding the linear fm mod
> to it. this
> has been completed and works quite well - *if you have any d.i.y.
> interest,
> look at this mod* - it is totally simple (and i simplified my
> set-up a bit
> more by skipping the ac / dc coupling switch,i went with ac only)
> - 1 jack, 1
> pot and 1 cap.. since the pot value wasn`t specified, i used a 50k as all
> the other pots in the module were 50k and it seems to work fine.
> this one is a winner ! :^)
> i`ve always liked the a-110, i consider it the "volks - vco" as it is
> adequate for most of my vco needs while remaining affordable and
> the lin fm mod
> gives it even more bang-per-buck !
> i didn`t add the soft sync option as i don`t use sync that much
> but i may go
> back and retrofit it - i did have a question about it though - it shows a
> jack and pot but what is the pot for - i didn`t think it would
> be needed for
> a sync input - some sort of range control -
> thanks !
> best,
> dave

Dave,

sorry for the late reply - but I had to understand the A-110 softsync
circuit before I answer. The attenuator at the optional softsync input does
make sense. As you probably know the A-110 has a sawtooth core. The
comparator that triggers the discharge (or reset) of the sawtooth has
normally a trigger threshold of 0V/GND. With the optional softsync the
trigger level of the comparator can be modulated with an external signal.
Different levels of the same soft sync signal lead to different results as
the trigger threshold of the reset comparator is modulated with different
amplitudes.

In contrast attenuation of the hard sync signal would not make much sense:
in this case the sync would simply stop below at a certain level.

Best wishes
Dieter Doepfer